Lecture 17: Cryptosporidiosis and Coccidian diseases Flashcards
Eimeria, cystioisospora, toxoplasma, neospora, and sacrocystis are all types of ___
Coccidia
Coccidians and cryptosporidium infect cells of ____
GI and extra intestinal sites
What are the two life stages of coccidia and cryptosporidium
Zoie and oocyst
What is the Zoite life stage
Elongated, motile cells
Invade host cell
What is the oocyst life cycle stage
Environmentally resistant stage, shed in feces
Oocysts contain infective ___ typically located within ____
Sporozoites, sporocysts
T or F: most cryptosporidium are host specific
True
What is the host for cryptosporidium cuniculus
Rabbits
What species of cryptosporidium is the exception to host specificity and infects ruminants, horses and humans
C. Parvum
How is cryptosporidium transmitted
Ingested or inhaled
Describe the direct life cycle of cryptosporidium
- Oocyst ingested/inhaled
- Sporozoites excyst
- Infect host cells
- Develop into meronts
- Schizogeny
- Gametogeny
- Fertilization
What is schizogeny
- Meronts divide into type I meront
- Type I meronts form merozoites
3, merozoites infect host cells
What is gametogeny
Subset of merozoites infect host cells and develop into gamonts—> gametes
Describe fertilization in the enteric cycle
- Zygotes develop into oocysts
- Sporogeny- oocysts sporulate endogenously
- Thin walled oocysts- Sporozoites excyst and reinfect host (auto-infection)
- Thick walled oocysts: exit host, infective when shed, via bale for months
Do cryptosporidium have endogenous or exogenous sporogeny
Endogenous
How does auto-infection occur in cryptosporidium
Thin walled oocysts become Sporozoites and reinfect host
What are the two broad types/diseases that cryptosporidium can cause
- GI
- Respiratory
T or F: most hosts with GI cryptosporidosis have mild to moderate, self limiting diarrhea
True
The severe form that is potentially fatal for GI cryptosporidosis is common in….
Immunocomprimised hosts or animals with concurrent infections
what two species of cryptosporidium typically cause GI cryptosporidosis
C. Parvum and C. Baileyi
What is the causative agent/species of GI cryptosporidosis for ruminants and horses
C. Parvum
What is the causative agent/species for of GI cryptosporidosis in poultry
C. Baileyi
What species is respiratory cryptosporidosis commonly seen in
Avian
What is the causative agent of respiratory cryptosporidosis in birds
C. Baileyi
How do you diagnose cryptosporidosis
Microscopy (acid fast stain), ELISA, PCR
What stain is preferred for cryptosporidosis
Acid-fast
What is the treat for cryptosporidosis in dogs and cats
Paromomycin
What is the treatment for cryptosporidosis in calves
Nitazoxanide
T or F: eimeria spp have narrow host specificity
True
What species does eimeria have the largest impact on
Ruminants and poultry
Where do eimeria species infect
GI tract: enterocytes and/or cells within the lamina propria
What is the predilection site for E. Tenella
Cecum
What type of lifecycle do eimeria have
Direct life cycle
How is eimeria transmitted
Fecal-oral transmission
T or F: eimeria have an enteric cycle
True
Enteric life cycle: schizogeny, gametogeny, fertilization, oocyst production
Do eimeria sporulate endogenously or exogenously
Exogenously
What is damaged by eimeria induced coccidiosis that causes mild to moderate disease
Epithelium
What is damaged by eimeria induced coccidiosis that causes severe disease
Damage to epithelium and tissues within lamina propria
What is the eimeria or cattle
E. Bovis and E. Zuernii
What does E. Bovis and E. Zuernii cause in cattle
Bloody stools and tenesmus in calves
What is winter coccidosis for E. Bovis
Severe cold provokes disease even at low infection levels
What is nervous coccidiosis in E. Bovis
Enteritis and neurological disturbances, mainly seen in coldest months
T or F: sheep and goats are hosts for many of the same eimeria species
False, high host specificity
What is the eimeria spp. that infects poultry
E. Tenella
What is the preferred fecal test for diagnosing eimeria
Fecal float
What is the preferred anticoccidal drug for cattle, small ruminants and poultry against eimeria induced coccidiosis
amprolium
T or F: cystsospora have high host specificity
True
Where do cystoispora primarily infect
GI tract, infect enterocytes
What type of lifecycle do cystoisospora have
Direct
What types of transmission does cystoispora have
Fecal-oral transmission and paratenic hosts
What are the common paratenic host for cystoisospora
Rodents
How does the paratenic host infect the definitive host
Paratenic host ingest oocyst and Sporozoites encyst and form tissue cysts which are infective to definitive host
T or F: cystoispora have an enteric cycle
True
Does sporulation take place exogenously or endogenously in cystoisospora
Exogenously
What is the species/causative agent of cystoisospora coccidiosis in swine
C. Suis
What pigs are commonly infected with C. Suis
Neonates
What is the species/causative agent of cystoisospora coccidiosis in dogs
C. Canis
What is the species/causative agent of cystoisospora in cats
C. Felis and C. Rivolta
What is the definitive host for toxoplasma gondii
Felids
How are cats infected with toxoplasma gondii
Eating tissue cysts harbored in infected intermediate hosts
T or F toxoplasma gondii has an enteric cycle
True
Do oocysts sporulate exogenously or endogenously in toxoplasma gondii
Exogenously
Describe the extra-enteric cycle of toxoplasma gondii that occurs in intermediate hosts
Tachyzoites develop and rupture out of SI and mesenteric lymph node cells
Tachyzoites then infect cells throughout body
Cause acute toxoplasmosis and can infect placenta and fetus
Tachyzoites form ___ containing ____ in CNS, muscle and visceral organs
Tissue cysts, bradyzoites
T or F: bradyzoites only infect intermediate host.
False, bradyzoites are infective to intermittent and definitive host (felids)
What phase causes chronic toxoplasmosis
Tissue cyst phase
Which host (intermediate or definitive) dose acute toxoplasmosis occur in
Intermediate
Which host (intermediate or definitive) does chronic toxoplasmosis occur in
Both
What species does toxoplasmosis commonly cause abortion and stillbirth
Small ruminants- sheep and goats
T or F: treatment of toxoplasmosis eliminates bradyzoites in tissue cysts (chronic toxoplasmosis)
False
What is the definitive host for neospora caninum
Dogs
How is neospora caninum transmitted
Ingestion of tissue cysts harbored by intermediate host
Does neospora caninum have endogenous or exogenous sporulation
Exogenous
Describe the extra enteric cycle of neospora caninum
Tissue cysts embed primarily in CNS and muscle causing a life long infection
T or F: neospora caninum can be transmitted placentally
True
What is the intermediate host for neospora caninum
Cattle
Describe the symptoms experienced by puppies with neosporosis
Hindlimb paresis with hyperextension, muscle atrophy, cervical weakness and dysphasia
(Subclinical typically)
What are some symptoms experienced by adult dogs with neosporosis
Multifocal CNS and polymyositis, myocarditis, dermatitis, pneumonia, hepatitis, peritonitis, in continence
What species does neosporosis cause abortion in
Cattle
Cattle with neosporosis that give birth often have fetuses that are ____
Autolyzed, mummified, still born
What species of neosporosis do horses get
N. Hughesi
What does N. Hughesi cause in horses
Equine Protozoa myeloencephalitis- spinal cord and brain lesions
T or F: sarcocystis have broad host specificity
False, very strict
What is the one species of sarcocystic that has various intermediate hosts and therefore not highly host specific
S. Neurona
What is the definitive host for sarcocystis
Carnivorous and omnivorous mammals, birds and reptiles
How is sarcocystis transmitted
Ingestion of tissue cysts (sarcocysts) in striated muscle of infected intermediate hosts
What species of sarcocystis infect cattle
S. Cruzi
What is the definitive host for S. Cruzi
Dogs
What species of sarcocystis infect sheep
S. Tenella
What is the definitive host of S. Tenella
Dogs